I am not sure what the bottle necked rounds in the clip are, but they are not for that gun unless it has been altered.
There are barrels available for 9mm Parabellum and the gun is convertible just by changing barrels (the Germans converted tens of thousands in the WWII era, and marked them "08").
Someone called it "the other 1911" and it was a very durable and reliable pistol, used by the Austrians and Germans through WWII, though in a secondary role in the latter conflict.
A recent article on them repeated the old saw that the barrel was locked by the torque of the bullet engaging the lands; nonsense. The barrel is mechanicaly locked to the slide until the bullet leaves the barrel, just like any other locked breech recoil-operated pistol.